Landscape Ecology

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Traditionally, research in wildlife and fisheries has focused on population or community dynamics on relatively small or undefined spatial scales, with the size of a study area defined by protocols for collecting data or by management units such as forest stands or agricultural fields. Recent work in the field of landscape ecology strongly suggests that many ecological processes of interest to wildlife and fisheries researchers and managers occur on a variety of spatial scales, ranging from local (e.g. stand-scale) to regional (e.g. landscape-scale) dynamics. Landscape processes often are an emergent ecological property that cannot be directly extrapolated from observations collected on small scales. Inferences from small-scale or aspatial studies could be misleading in addressing the large scale ecological effects of increasing urbanization, changes in land use, and habitat fragmentation evident on modern landscapes.

Recent advances in technology are making spatially explicit data covering large areas widely available at relatively low cost. These data and the tools required to access and interpret them are rapidly becoming essential and affordable to wildlife and fisheries biologists. The Unit will develop research that quantifies and evaluates large-scale, landscape processes for wild populations and the ecological communities that sustain them. The Unit will also be involved in other landscape approaches, including the development and application of spatially explicit, individual-based behavioral models and the use of landscape characteristics to predict the distribution of wild populations. 

Projects:

Assessing the scientific basis for standards/practices at multiple spatial scales – East

Aquatic Gap: Regional Analysis of Biodiversity in the ACT/ACF Basins (completed)

ACT Aquatic GAP and water quality modeling (completed)

Gap Analysis for Alabama

Development of a decision support tool and procedures for evaluating dam operation in the Southeastern United States (completed)

Carbon sequestration and natural longleaf pine ecosystems

Biodiversity of terrestrial vertebrates on the J.D. Martin Skyline Wildlife Management Area and adjacent lands

Adaptive management and monitoring for restoration and faunal recolonization of shoal habitats

Inventory and conservation planning for species of greatest conservation need on Alabama DCNR lands

Assessing the scientific basis for standards/practices at multiple spatial scales--East

Funding Source: National Council for Air and Stream Improvement (NCASI), National Commission on the Science of Sustainable Forestry (NCSSF)

Principal Investigator: Mike Mitchell

Research Associate: Scott Rutzmoser

Student: Michelle Smith

Duration: August 2002 – December 2008

Forest managers, policymakers, and the public need better information about the relationship between biodiversity and the structure of forest stands and landscapes. At present, results of stand-level studies suggest that biological diversity is positively related to the structural/compositional complexity of stand-level habitat and that biological diversity is diminished when stand structures are simplified. Some ecological theories (e.g., the “intermediate disturbance hypothesis”) however, suggest that diversity at larger spatial scales may be positively associated with habitat heterogeneity. Yet, few studies have evaluated these relationships at multiple spatial scales, from the stand through the landscape level, or considered variables that may influence competitive exclusion. This project will make use of 3 large-scale wildlife habitat studies in highly forested landscapes in Arkansas, South Carolina, and West Virginia. These studies have characterized (or are currently characterizing) relationships between forest structure and presence of selected wildlife taxa at multiple spatial scales. Furthermore, the three sites encompass a range of vegetation types, structures, and physiographic settings across the Southeast.

The project included two workshops and a synthesis/analysis of data. The first workshop brought together collaborators to present methods and results, organize the synthesis, identify strategies for building a combined dataset, and select appropriate analytical methods. The second workshop presented the synthesis results to the same group for peer-review and comment. Preliminary results show a strong association between community structure for birds and heterogeneity of forest ages and types at multiple scales. The expected result of this study is an analysis of relationships among biodiversity, forest structure, and other ecological factors (e.g., productivity) at multiple spatial scales. It will provide a foundation for the design of forest management approaches that sustain biodiversity, and it will help identify criteria and indicators for use in evaluating the performance of sustainable forestry programs.

Status – Funding for a PhD student to continue and further develop landscape analyses using the NCSSF data set was recently awarded from NCASI. Michelle began working toward her PhD on this project last Fall and will be investigating fundamental ecological processes that influence landscape patterns, how these processes and patterns vary with spatial and temporal scale, as well as developing landscape models for predicting the effects of forest management on biodiversity.

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Aquatic Gap: Regional Analysis of Biodiversity in the ACT/ACF Basins (completed)

Funding Source: U.S. Geological Survey

Principal Investigator: Elise Irwin, James Peterson (GACFWRU), Byron J. Freeman (University of Georgia), Liz Kramer (University of Georgia)

Collaborator: Mary Freeman (USGS, PWRC)

Research Associate: Deanne Moosman

Research Assistant: Kevin Kleiner

Student: Cari Ann Hayer

Duration: September 2001 - August 2005

We developed Aquatic GAP applications for two centers of aquatic biodiversity, the Alabama-Coosa-Tallapoosa (ACT) and Apalachicola-Chattahoochee-Flint (ACF) river basins. The ACT and ACF basins span broad ranges of physiographic settings and harbor exceptionally high levels of species richness and endemism, providing ideal opportunities for testing current (MORAP) and new approaches and refining them to predict species occurrences and community attributes in relation to physical variables. Our project is based on the fundamental assumption that watershed characteristics (e.g., soils, vegetation, elevation, relief, land use) and geomorphic history directly influence stream structure and function and that these, in turn, influence the aquatic community. These influences, however, occur in systems with high natural variability that must be assessed and quantified. Further, we assumed that the ultimate goal of this project was to develop products that could be used by natural resource managers for decision-making; hence, they should include quantifiable measures of uncertainty. Therefore, we will develop probabilistic models using historic and current empirical data on the distribution of aquatic species in the basin to ultimately provide a decision support system for resource managers.

Status – We provided technical review for the 12-digit hydrologic unit codes in the Tallapoosa Basin and will complete review for the ACT. The faunal database is complete and models related to watershed features (all layers complete) have been constructed. We constructed KNN models for 63 species in the Tallapoosa River basin. The species-specific models of species presence within sample reaches in the Tallapoosa River Basin were relatively accurate with classification error rates for presence, absence, and across categories (overall error) averaging 16.2%, 21.5%, and 20.5%, respectively. Predictions at the subwatershed level were conducted using the best model for each species. Maps depicting probability of presence were generated for each species. Our modeling efforts have provided valuable insight into the factors influencing species distribution and community structure in portions of the ACF and ACT Basins (This study; Freeman et al. 2003; Peterson et al 2003). The final report was completed in draft form in December 2004; still pending comments from National GAP.

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ACT Aquatic GAP and water quality modeling (completed)

Funding Source: Alabama Division of Wildlife and Freshwater Fisheries

Principal Investigator: Elise Irwin and Diane Hite (Auburn University)

Research Associate: Gareth Turner

Duration: October 2004 – September 2006

The Southeastern Aquatic GAP project was initiated to identify conservation areas in river basins where aquatic biodiversity and endemism are higher than other temperate rivers. As part of a regional assessment of the Alabama-Coosa-Tallapoosa (ACT) and Apalachicola-Chattahoochee-Flint (ACF) basins, we have developed techniques to incorporate geospatial data to analyze aquatic species distribution in relation to local and landscape features and identify conservation potential of specific subwatersheds. Two portions of the ACT have been completed under a previous contract with the U.S. Geological Survey; this project will assess an additional 27,700km² of large river basin habitat (25% of Alabama’s riverine habitat) for conservation potential in Alabama. The resulting database will include species and community data for over 184 freshwater fishes and all mussel species from the ACT. Limited data on crayfishes and aquatic herpetofauna are also available for model construction. Completion of the ACT Aquatic GAP will allow for development of decision support systems (DSS) to help natural resource managers make informative decisions for land and riverine management and landscape level conservation planning. In addition, we will develop water quality-land use economic models that will be valuable for assessing restoration activities. Water quality models will also be applied to relate faunal distributions to landscape and land use variables (including economic assessment of land use and potential for land use change). These will be exceptional contributions to the DSS.

Status – Based on watershed characters, we constructed predictive models for the distributions of 79 fish species. Important predictive landscape variables included stream reach and watershed characters such as stream order, stream density (km/ha), road density (km/ha) and stream reach elevation (m). In addition, juxtaposition of habitats was important in prediction of species presence, including isolation of stream reach and link magnitude. Finally, Land Use/Land Cover (LULC) variables (e.g., % row crop agriculture or forested land) and parent geology (e.g., % felsic orthogneiss or cataclastic rock) were significant variables for predicting presence of many species. Total model error rates were low (< 23% overall) and given that error rates are an estimate of the uncertainty in prediction of species occurrence (in the form of a probability), these error rates can be directly incorporated into conservation decision making. The final report for this project is complete; it may be accessed at: http://www.outdooralabama.com/research-mgmt/State%20Wildlife%20Grants/ACT%20GAP%20Final%20Report.pdf. Maps depicting these predicted distributions were generated for use in conservation planning and decision-making, and are located at www.southeastaquaticgap.org/research.htm.

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Gap Analysis for Alabama

Funding Source: U.S. Geological Survey

Principal Investigator: James B. Grand, Elise Irwin, Mike Mitchell, and Mark MacKenzie (Auburn University)

Project Coordinator: Amy Silvano

Research Assistant: Kevin Kleiner, Ben Taylor, Gareth Turner

Student: John Hogland

Student Workers: James Grand

Duration: August 2000 – December 2007

Alabama spans five physiographic provinces from the Coastal Plain through the Interior and Appalachian Low Plateaus, more than any other state. Within these provinces unique and often rare communities and diverse assemblages of plants and animals exist. Without adequate planning for conservation based on sound scientific information these communities may ultimately disappear. Gap analysis is directed towards identifying native animal species and natural communities that are underrepresented in conservation efforts. The objectives of the project are: (1) to promote cooperative approaches toward the development and use of Gap data, (2) to map the existing natural and semi-natural land cover; (3) to produce maps of the predicted distributions of every vertebrate species; (4) to map the ownership of public and private conservation lands; (5) to categorize all lands according to management status; (6) to produce a database of the total surface area and relative representation for each class of land cover and animal species relative to land stewardship categories; (7) to produce a written report of the mapping, assessment, analysis methods, results, accuracy, and limitations; and (8) to develop a plan for the maintenance and updating of the information.

Status – All products for the gap analysis have been completed, including the land cover map, vertebrate predicted distribution maps, and stewardship maps. Provisional versions of these data sets are currently available to the public for download from our website (www.auburn.edu/gap). A gap analysis of land cover and vertebrate species has been compiled and richness maps for each major taxa group and overall species richness have been generated. Metadata for each GAP component has been completed and a written report of our methods is currently underway. The final methods report will be turned into our National GAP office for review by year end 2007 and all GAP products will be considered provisional until the reviews have been completed. 

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Development of a decision support tool and procedures for evaluating dam operation in the Southeastern United States (completed)

Funding Source: U.S. Fish and Wildlife Service

Principal Investigator: Elise Irwin and James Peterson (GACFWRU)

Research Associate: Kathryn Mickett

Duration: June 2002 – December 2005

This project will create a template on which to base future efforts incorporating decision analysis and adaptive management into the Federal Energy Regulatory Commission dam re-licensing process by developing a model for implementation of adaptive flow management for Harris Dam on the Tallapoosa River, Alabama. To do so, we will address the following objectives: (1) determine stakeholder values and objectives; (2) develop models relating aquatic community (specifically, fish and mussels) responses to changes in habitats and flow regime; (3) develop decision models for evaluating the impacts of current and alternative dam operating procedures on (stakeholder) valued outcomes; and (4) develop explicit recommendations for alternative dam operating procedures that will produce the information for resolving key uncertainties about the effect of dam operation on the aquatic community.

Status - The workshop, “Adaptive Management Below Dams” was held April 29 through May 1 2003. Guest speakers James Nichols (USGS, Patuxent), Mike Conroy (GACFWRU), and James Peterson (GACFWRU) gave presentations in their fields of expertise. Several important stakeholder groups were represented at this workshop, including (but not limited to) USFWS, ADCNR, Alabama Power, Alabama Rivers Alliance, Middle Tallapoosa River Conservation Association, Upper Tallapoosa Watershed Committee, and Lake Wedowee Property Owners’ Association. An interactive forum was facilitated to address common issues among all participants of the workshop. Points of discussion included objectives and values, governance, and decision-making principles. Following this inclusive interactive discussion, a similar forum was opened involving participants with a stake in the adaptive management process at R.L. Harris Dam. The product of this forum was an official stakeholders group with proposed purposes and objectives. Since this initial meeting, there have been three meetings of the R.L. Harris Stakeholders Board. A website (www.rivermanagement.org) has been created and an official charter has been drafted and accepted. An initial decision support computer model has been created with the program NETICA. This model is currently, and will continue to be, under modification as discussion of the board continues and new data become available. Decisions have recently been made to apply a flow adjustment at R.L. Harris that matches the gage reading at Heflin. Flow management was implemented in Spring 2005 and monitoring protocols have also been implemented. The final report was complete in October 2006.

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Carbon sequestration and natural longleaf pine ecosystems

Funding Source: U.S. Geological Survey, U.S. Fish and Wildlife Service

Principal Investigator: John Kush (Auburn University)

Graduate Student(s): Ram Thapa, John Gilbert

Student Technicians: Anshu Shrestha, Arpi Shrstha

Duration: July 2003 – September 2008

Forested ecosystems have a significant potential for sequestering large amounts of carbon through land management. To fully realize the potential carbon sequestration capabilities of these ecosystems there is a need to develop strategies and methods for increasing carbon sequestration. A fire-maintained, longleaf pine dominated ecosystem may offer one of the best options for carbon sequestration among the forested ecosystems of the southeastern US while providing habitat for a number of threatened and endangered plant and wildlife species, including red-cockaded woodpeckers, gopher tortoises, indigo snakes, etc … (Hardin and White 1989, Landers et al. 1995, Jackson 1989). Among the southern pines, longleaf may offer the best opportunity for carbon sequestration. It is the longest-living of the southern pines, capable of growing to 500 years (Platt et al. 1988). It will continue to put on growth, even at older ages (West et al. 1993). Products from longleaf pine will sequester carbon longer than most since they are likely to be solid wood products like structural lumber and poles. In addition to the tree itself, a fire-maintained longleaf pine ecosystem supports a productive understory of grasses and herbaceous plants which themselves may offer more carbon storage than the trees. Objectives of the study are: Phase I – Develop a detailed literature review/bibliography of research literature related to longleaf pine, above and below ground biomass, and carbon sequestration; Phase II – Determine the relationships between prescribe burn treatment and above/below ground biomass and carbon sequestration; Phase III – Determine the relationships between root biomass/carbon sequestration and the density, site quality, and age of the longleaf pine overstory.

Status – The season of burn study plots on the Escambia Experimental Forest in Brewton, AL have been extensively sampled to address the status of carbon in the no-burn, spring, summer and winter season prescribed burn plots. Longleaf pine heights and diameters were measured. Longleaf pine biomass was calculated from these measurements using developed weight and volume equations. Herbaceous (forbs and grasses) and woody (tree and vine) vegetation and litter were collected from each plot. The vegetation and litter was oven-dried and weighed. A sub-sample of the dried vegetation from each component from each plot was ground up and analyzed for carbon. The resulting percent carbon was used to calculate the carbon sequestered in each component. The preliminary results were presented at a meeting in early 2005. Work was completed for the soil samples and the vegetation and soils data is being used by Ram Thapa for his master’s degree. Work will begin on Phase III in November 2006. This will have an impact on the plots we will be able to use in Phase III of the study. The search continues for another graduate student to work on more of Phase II and all of Phase III.

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Biodiversity of terrestrial vertebrates on the J.D. Martin Skyline Wildlife Management Area and adjacent lands

Funding Source: Alabama State Lands Division

Principal Investigator: James B. Grand, Eric Soerhen, and Yong Wang (Alabama A&M University)

Research Associate: Nick Sharp and Shannon Allen

Student(s): Alan Hitch (Ph.D.), Florence Chan (M.S. - AAMU)

Research Assistant(s): Megan Binkley, Helen Czech, Jeff Sorrell, Carrie Johnson, James Fuller

Duration: January 2005 – August 2008

Little has been published regarding the composition and habitat requirements of terrestrial vertebrate communities using the forests of the southwestern Appalachian Ecoregion in Alabama. This region represents the southernmost extent of the range for many species native to Appalachian Mountains. Thus, the native fauna and flora includes many vertebrates that are found nowhere else in the state. Recent land acquisitions in Jackson County bring the total acreage under state management on the Wildlife Management Area and Forever Wild lands to over 28,000 acres. We propose to perform a comprehensive inventory of terrestrial vertebrates using these lands based on methods that incorporate rigorous statistical design, and estimation of detection rates, which often obfuscate the results of wildlife inventories. Inventory data will be used to develop probabilistic models of wildlife habitat relationships that can in turn be used to map the distribution of the dominant ecological systems and animal communities on the area. These results will ultimately be used to develop a GIS for use in planning conservation and management based on high probability of use by high priority species and areas of high biodiversity. This is a collaborative project with the Alabama Lands Division Natural Heritage Program, and Alabama A & M University.

Status – Based on strata derived from models of landform and solar exposure a stratified-random selection of 176 points was selected for sampling over the 2005 and 2006 field seasons. Point counts methods were used to survey breeding birds twice during May 15-June 30 2005 and 2006. Line transect methods were used to survey reptiles and amphibians during April-July and again in August-November 2005 and 2006 at the same 88 points. Live traps were used to sample small mammals at 88 points 15 September-15 November 2005 and 2006. Vegetation was inventoried and classified all 176 points. These data will be used to validate land cover maps developed from the AL-Gap Project, and develop habitat relationship models after accounting for detectability of animals. Data and models will be used to develop a GIS suitable for making management decisions on the properties that were sampled. This project was extended one year and expanded to include a survey to examine differences in productivity of selected bird species among habitats on the study area. The additional survey was completed during summer 2007. Analysis of the distribution and abundance data is underway.

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Adaptive management and monitoring for restoration and faunal recolonization of shoal habitats

Funding source: Alabama Power Company, Alabama Division of Wildlife and Freshwater Fisheries

Principal Investigator: Elise Irwin

Research Associate (s): Kathryn Mickett and Gareth Turner

Student (s): Taconya Piper (Ph.D.), Ben Martin (M.S.)

Duration: October 2006 – September 2011

High imperilment rates of fishes and mussels in the state of Alabama are related to impoundment and regulation of riverine flows. Specifically, the inundation and disruption of natural flow regimes of shoal habitats in medium sized rivers was hypothesized to be the primary cause for imperilment of 53% of fishes in Southeastern Rivers. In Alabama, loss of functional shoal has likely affected 64% of fish species of greatest conservation need (GCN). Restoration and protection of functional shoal habitat in the remaining unimpounded (i.e., free flowing) fragments of rivers of the State is a critical element of conservation of aquatic species. However, effects of specific flow regimes (i.e., magnitude, duration and timing and their combinations) on shoal habitats and ultimately on biotic processes are not well known. Mixed results regarding success of implementation of minimum flow regimes have illuminated the need for process oriented research that evaluate effects of flow regimes on aquatic fauna that depend on functional shoal habitat. In addition, these data would be transferable to the many shoal dependent GCN species in other river basins. Therefore, we propose to evaluate effects of experimental flow regimes on shoal dependent aquatic fauna in the Piedmont region of Tallapoosa River. Specific objectives are to: 1) Compare fish and invertebrate assemblages and population structure between flow-managed and naturally flowing river reaches (including all GNC species); 2) Assess habitat stability (i.e., shoals) and persistence for GCN species and other species of concern; and 3) Determine applicability of flow management and habitat restoration for other river systems.

Status - Extinction/colonization rates were estimated from a long-term (1981-1991) historical data set collected by backpack shocking after Harris Dam was constructed. Results indicated that for most species, group (regulated vs. unregulated) was not an important covariate for explaining the variation in the data. In addition, extinction and colonization were estimated as either equal or constant over all time periods, with colonization always greater than extinction when rates were constant. This suggests potential recovery for some species since the dam was constructed. Monitoring of flow management changes at Harris Dam has been conducted in both the spring and fall of 2005-2007. Results from 2005 indicated group (regulated vs. unregulated) and/or distance from the dam as important factors in explaining the variance in occupancy for several species, including black redhorse, speckled madtom, lipstick darter, and muscadine darter. In addition, spawning windows for fishes are being evaluated for GCN species from both assessment of reproductive condition of adults and collection and aging of juveniles. Data from 2006 and 2007 are currently being processed.

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Inventory and conservation planning for species of greatest conservation need on Alabama DCNR lands

Funding Source: Alabama Division Wildlife and Freshwater Fisheries

Principal Investigator: James B. Grand

Co-principal investigators: Mike Gangloff, Craig Guyer, Elise Irwin, Carol Johnston, Mark MacKenzie, Ed Loewenstein

Project Coordinator: Amy Silvano

GIS Specialist: Gareth Turner

Graduate Students: Carrie Johnson, Patricia Spears, Dan Holt, Kevin White (Appalachian State), and 4 vacancies.

Duration: October 2006 – December 2011

During this five-year project the Alabama Cooperative Fish and Wildlife Research Unit will coordinate the development of multi-species Inventory and Conservation Plans (ICPs) for selected lands managed by the Alabama Department of Conservation and Natural Resources. The project will potentially include lands in six ecological regions, and could affect 303 species of greatest conservation need (GCN), of which 118 are listed as threatened or endangered. During the first year, a steering committee will be established, lands and species for inclusion in the plan will be identified, information needs assessment will begin, and an outreach plan will be developed. Subsequent years will be used to gather information and develop decision support tools, conduct outreach programs, and develop the ICPs.

The overall goal is to provide a science-based plan for the conservation of GCN species and the habitats they depend on as they occur or could occur on ADCNR managed lands. Additional goals are to establish a protocol and a baseline for monitoring GCN species, to provide a basis for the development of new ICPs, to provide guidance for the improvement of populations of GCN species, to improve upon our understanding of the issues affecting the conservation of GCN species, and to foster relationships among public and private stakeholders.

Status – The first year of the project has been dedicated to the identification of study sites, development of survey design, and assembly of GIS data. Two meetings were held with DCNR Steering Committee to select study areas and refine the project objectives. As a result, 13 study sites were selected on DCNR lands. Numerous meetings have been held with the Co-PIs to develop and refine the survey design and protocols and review the available GIS data. A stratified random sampling approach was selected for both aquatic and terrestrial surveys. Aquatic surveys will be stratified based on stream order and watersheds. Terrestrial surveys will be stratified using Alabama GAP land cover data and allocated based on expected species diversity. Six graduate students have been recruited for the project and two positions are vacant. Surveys will begin in January of 2007 on 4 study sites in southern Alabama.

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